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Strawberry crown moth

Synanthedon bibionipennis

1 host plant

Last updated

Data Coverage 2 of 6 dimensions
Host Plants
GDD Threshold
Peak Activity
Damage Severity
Monitoring
Regional Notes

Strawberry crown moth larvae tunnel into the crowns and roots of strawberry plants and certain woody hosts. Look for wilting or dying crowns, sawdust-like frass at the base of plants, and small entrance holes. Host records list Mediterranean plants like strawberry tree (Arbutus unedo).

Monitor plant crowns regularly for signs of larval activity. Remove and destroy infested plants to prevent spread. Since this pest is uncommon in many regions, no large-scale control strategy is standard. Maintain healthy plant vigor to support recovery from minor infestations. Avoid moving infested stock between plantings.

Quick Reference

Order
Lepidoptera
Type
borer
Host Plants
1
GDD₃₂ Emergence (est.)
1,778

Strawberry crown moth Emergence (est.) typically begins around 1778 GDD₃₂. As of April 3, 2026, Puget Sound stations range from 1070 to 1180.6 GDD₃₂, approximately 597 units before the expected threshold.

Regional Season Tracker

GDD₃₂ accumulation across 7 Puget Sound stations · as of Apr 3, 2026
Station GDD₃₂ Current Stage Next To Go
Issaquah / East King 1,181 Pre-season Emergence (est.) 597
Seattle / UW 1,171 Pre-season Emergence (est.) 607
Kent / Auburn 1,111 Pre-season Emergence (est.) 667
Olympia / Tumwater 1,106 Pre-season Emergence (est.) 672
Bellingham / Whatcom 1,101 Pre-season Emergence (est.) 677
Tacoma / Puyallup 1,075 Pre-season Emergence (est.) 703
Sequim / Rain Shadow 1,070 Pre-season Emergence (est.) 708

Source: Pest GDD Catalog, UMD IPMnet. Adult emergence at 468 GDD₅₀ from genus-level Synanthedon spp. models. No species-specific GDD model published for S. bibionipennis. PNW Handbooks confirm adults emerge June-July in PNW (consistent with 468 GDD₅₀ timing). Best available estimate. Added 2026-04-03. About GDD₃₂ →

What Damage Looks Like

The strawberry crown moth is an insect native to the PNW and has caused damage to strawberries in the northern Willamette Valley. The adult strongly resembles a yellow jacket; it is about 12 to 15 mm in length, black with yellow markings. The eggs are brown, oval, sculpted on the surface, and distinctly cupped on the sides. The larvae are white with a brown head, and 16 to 25 mm in length at maturity. Larvae feed on the crown and root tissue of the strawberry plant. This feeding provides entry...

Cultural Controls

  • -cultural control No commercial strawberry varieties resistant to SCM are available.
  • Untopped strawberry plants can serve as trap plants.
  • If plants are topped before the moth's flight period, a few rows should be left untopped.
  • Egg-laying females are attracted to and deposit a significant portion of their eggs on the untopped plants.
  • These untopped plants are then disked under in the fall.
  • Remove infested plants.

Host Plants (1)